柴达木盆地东部荒漠植物生态位特征

以柴达木盆地东部27个典型样地的植物群落为研究对象,通过生态位宽度和生态位重叠指数计算,分析该区13种优势植物在土壤含水量、容重、有机质、pH、全盐、全氮维上的生态位特征,以期为柴达木盆地植被恢复重建和荒漠系统生态保护提供理论参考。结果表明:①13种植物在6个土壤因子上平均生态位宽度从大到小依次是:驼绒藜、琵琶柴、芨芨草、芦苇、合头草、蒿叶猪毛菜、白刺、盐爪爪、小嵩草、麻黄、沙拐枣、柽柳和梭梭,其中,驼绒藜在土壤含水量、容重和有机质上占据最高值,琵琶柴在土壤pH、全盐、全氮维上占据最高值;②生态位宽度较大的物种在生态位重叠上并不占据最高重叠值,而是处于一个中游的位置;③驼绒藜和琵琶柴在生态位宽度和生态位重叠上均占相对高的位置,对群落的建群起重要作用;④78个种对在每一个土壤因子上的生态位重叠值0.3的占总对数的比例为76%,柴达木盆地东部植物总体生态位重叠偏低,竞争较小,群落处于一个相对稳定的状态。

Ecological niche characteristics of desert plants in the eastern Qaidam Basin

Selecting plant communities of 27 typical sample plots in the eastern part of Qaidam Basin as research object, we analyzed the niche characteristics of 13 species of dominant plants in dimensions of soil moisture content, bulk density, organic matter, pH, total salt, total nitrogen through the niche breadth and niche overlap index calculation. In order to provide theoretical reference for vegetation restoration and ecological protection in Qaidam Basin. The results showed that: (1) the average niche breadth of the 13 species of plants on the soil of six factors in descending order is as follows: Ceratoides latens > Reaumuria songonica > Achnatherum splendens > Phragmites communis > Sympegma regelii > Salsola abrotanoides > Nitraria tangutorum > Kalidium foliatum > Kobresia > Ephedra sinica > Calligogum kozlovi > Tamarix ramosissima > Haloxylon ammodendron. Among them, the areas vegetated by Ceratoides latens had the highest in soil moisture content, bulk density, and organic matter content, and those vegetated by Reaumuria songonica had the highest soil pH, total salt content, and total nitrogen content. (2) The species with large ecological niche width did not show the greatest overlap among their ecological niches; instead, they showed a moderate overlap. (3) Ceratoides latens and Reaumuria songonica occupy a relatively high position in terms of both the niche width and niche overlap, and they play an important role in community construction. (4) For each of the 78 species pairs, the proportion of the ecological niche overlap in each soil factor less than 0.3 was 76%. In the eastern part of Qaidam Basin, the overall ecological niche overlap of the plants was low, which implied that the competition is small and the communities are in a relatively stable state.